Statistics to Watch

The c-tree Server has numerous tuning options available to ensure the utmost in performance. Many of these options fall into several broad categories. Some specific areas to check when examining your c-tree Sever for the best performance are listed here.

• Are data/index cache hit rates high? (Approaching 100% is best for performance.)
• What % of data/index cache are in use? If not approaching 100%, increasing the data and/or index cache sizes might improve performance by reducing disk I/O.
• How many disk reads/writes per second? Do the I/O stats match expectations based on client operations?
• Is the number of active clients the expected number?
• How many concurrent locks? (Watch for an excessive number based on number of connected clients.)
• How many transactions/sec?

The following sections discuss how to use the performance monitoring abilities of the c-tree Server.

The c-tree Server Statistics Utility

The c-tree Server Statistics utility, ctstat, is a client utility used to display statistics collected by the c-tree Server. It is found in the client folder of the Server installation and demonstrates the use of the SnapShot function. This section describes the reports that this utility produces and how to use the utility to generate these reports.

The command-line usage for the ctstat utility is as follows:

ctstat <report_type> [-u <userid>] [-p <password>] [-s <servername>]

                     [-i <int> [<cnt>]] [-h <frq>] [-d]

where:

    <report_type> is one of:

        -vas                Admin-System Report

        -vts                Tivoli-System Report

        -vaf <file>...      Admin-File Report

        -vtf <file>...      Tivoli-File Report

        -vau <user>...      Admin-User Report

        -func               Function Timing Report

        -text               Write system snapshot to SNAPSHOT.FCS

    -u <userid>         Connect to c-tree Server using user ID <userid>

    -p <password>       Connect to c-tree Server using password <password>

    -s <servername>     Connect to c-tree Server using server name <servername>

    -i <int> [<cnt>]    Pause <int> seconds for optional <cnt> times

    -h <frq>            Print a description header every <frq> outputs

    -d                  Show cache stats as delta

Function Profiling

The c-tree Server Statistics Utility can also produce useful information about the timing of c-tree function calls. Use the following command line to produce function timing information:

ctstat -func -u ADMIN -p ADMIN -s FAIRCOMS -i 10

This information profiles the c-tree Server's operations. Knowing which functions the server is spending the most time performing can lead to insights into ways to better improve performance.

Analyze Statistics

You can capture all of the SnapShot statistics from the c-tree Server to a text file, SNAPSHOT.FCS, for later analysis. The following command line will enable this output in 30 second intervals

ctstat -text -u ADMIN -p ADMIN -s FAIRCOMS -i 30

The c-tree SnapShot Parser Utility, ctsnpr, is used to parse a SNAPSHOT.FCS into a text file in comma separated value format. You can use applications such as Microsoft Excel to view this file and graph the statistics. This method will help to visually observe patterns of activity over time.

Examples

Admin-System Report Example
Tivoli-System Report Example
Admin-File Report Example
Admin-User Report Example
Function Timing Report Example

Automatic Logging to SNAPSHOT.FCS

The c-tree Server supports automatically writing performance snapshots to the SYSLOG files. It can also write system snapshots in human- readable form to the SNAPSHOT.FCS text file. The following sections describe how to enable automatic snapshots.

Write system snapshots to the human-readable SNAPSHOT.FCS text file with the following DIAGNOSTICS options:

DIAGNOSTICS   SNAPSHOT_SHUTDOWN

DIAGNOSTICS   SNAPSHOT_AUTOMATIC

DIAGNOSTICS SNAPSHOT_SHUTDOWN writes a system snapshot to SNAPSHOT.FCS at the start of the server shutdown process. DIAGNOSTICS SNAPSHOT_AUTOMATIC writes any automatic snapshots to SNAPSHOT.FCS instead of to the SYSLOG files. However, only the system snapshot is written. Snapshots for activated users and/or files are ignored.

Performance Monitoring Using the SnapShot API

c-tree Server configuration options provide an easy way to enable automatic performance snapshots. Additional flexibility and access to the complete set of statistics maintained by the c-tree Server is available programmatically through the SnapShot c-tree API function. This API function:

• Controls automatic snapshots, overriding configuration options (if any).
• Writes snapshots to the SYSLOG files on demand, whether or not automatic snapshots are active.
• Writes system snapshots in human-readable form to SNAPSHOT.FCS .
• Returns snapshot data on-demand to the calling application program.

Conclusions

Performance monitoring is a vital activity to ensure your c-tree Server is performing in the most efficient manner. The c-tree Sever has a powerful statistics monitoring facility FairCom calls SnapShot. Regular examination of server statistics can help identify application bottlenecks, as well as potential problems with the c-tree Server environment.

In this article we have shown three ways to put the SNAPSHOT feature to use with your c-tree Server.

• The c-tree Plus Statistics Utility, ctstat, providing remote client monitoring.
• Automatic logging of c-tree Server Statistics via server configuration keywords.
• The SnapShot Programmatic API for direct use in your applications.

The c-tree Server SnapShot facilities provide MUCH more power than what has been described here. Complete details can be found in the documentation section of the FairCom web site.

www.faircom.com/support/ctreeDocs/pdf/fcupdate.pdf